Fluid-motor.



G. H GILMAN.

FLUD MTH.

AFPLlcAHoN msn 1ML 1. |915 Patented Feb. 4, E919.

In/ven/t-or:

llu im UN ITEI)` STATES PATENT OFFICE.

1,293,080. Specification 0f Letters Patent Patented Feb. 4, 1919. Application led January 7, 1918. Serial No. 70,864.

when the piston is in the cylinder 1 an a citizen of the Unlted States, and a resln important feature of one Hphase of 65 dent of Claremont, in the countyof Sulmy mvention is novel pressure `livan and State of New Hampsh1re,have trolling means whereby all reciprocatory invented an Improvement in Fluid-Motors, valve members other than the piston itself of Whichthe following description, in conmay be dispensed with, and whereby an nection with the accompanying drawings, exceedingly simple, efficient and economical 60 is a specification, like characters on the motor isfpresented. 4 drawings representing like parts. In the preferred construction illustrated, his invention .pertains to improve- I provide the piston with a reduced porments in direct acting Huid motors and tion 7 to which I may admit pressure fluid, more particularly, though not exclusively, preferably compressed air, from any suit- 65 to motors of the valveless type having a able source of supply, through an inletpasreciprocatory percussive piston adapted to sage 8. The reduced portion 7 is preferimpart rapidlyreeurring blows to the drill ably in connection with the intermediate steel of a rock drill. Y piston chamber 6 so that the pressure fluid e preferred construction of duid motor acting on the surface 9 of the larger piston 70 constituting one embodiment of my invenhead 4 Will start 4the piston on its forward tion illustrated in the drawings, shows a stroke. I prefer to provide a by-pass port valveless fluid motor which is simple in l0 so t at pressure fluid may flow from of pressure Huid and exchamber 2 to act on the rear surface 11 of 7b ceedingly effective as a percussive unit, Athe small piston head 5 t0 assist in proespecially when used in connection with an 'ducing forward movement of the piston. automatlcall rotated drill steel and pres- By varying the relativg sizes and locations sure iiuid fheding mechanism of any of o the openings from the sby-pass port 10 the Well-known types, but preferably of into the cylinder and from the inlet port 80 the type shown 1n my copending applica- 8 into the cylinder, and by varying the tion herewith filed, relative proportions of the reduced poreferring to the drawingswhieh show tion 7, I can provide 4for admission and a preferredV construction of one embodicut 01T of pressure fluid in any desired manment of my invention: 4 ner, but I prefer that the inlet port 8 B5 Figures 1 and 2. are longitudinal sections should be closed sufficiently early 1n the of a preferred construction of percussive stroke of the piston to provide a period iuid motor on the lines l--l-l of Fig. 3; of expansive action of the pressure fluid. Figs. 3, 4 and 5 are transverse sections on I prefer that the opening from the bythe ines 3- 3, 4`4, 5-5 respectively of pass port 10 shall befclosed prior to or co- 90' Fig. 1. incident with the exhaust of pressure fluidv Referring to the drawings, I preferably acting on the surface 9 of the pistonhead provide, as shown, a cylinder 1 having pis- 4. I prefer to move the piston on its opton chambers 2 and 3 of different diamposite or return stroke by the expansive eters, of which I prefer that the piston action of pressure Huid, and to this end I 96 chamber 2, of smaller diameter, shall be may provide a return port 13 inthe cylt e rear piston chamber and the iston inder Wall `adapted to exhaust pressure chamber 3, of larger diameter, shall e the fluid from the intermediate piston chamfront piston chamber. Cooperating with er 6 into the large.piston chamber 3. the cylinder'l I may pro'vide a piston mem- This return port 13 may be in constant 100 size to Work in the pistonchamber 3, and ber and in intermittent communication a piston portion 5 of proper size to Work in with the intermediate chhmber 6. I prefer the piston chamber 2. It will be noted that to so `arrange thls port 313 that it Shall be opened `by the piston shortly before the completion of the forward stroke thereof and preferably after communication between the intermediate piston chamber 6 and fthe by'-pass port 10 as beenclosed.

prefer that an exhaust ort 12 shall exhaust pressure fluid from tlie piston chamber 3, when the position of the piston is such as to permit such exhaust. I may, as shown, so arran e the effective opening of the inlet port 8 t at the syply of live airto the cylinderis cut o early in the forward stroke of the piston, thereby providing a period of pressure fluid expansion in the in- 15 termediate piston chamber 6 and preferably also in the piston chamber 3, I prefer to utilize the pressure fluid in the intermediate piston chamber 6 to return the piston, and to this end the return port 13 is preferably arranged as shown to connect the intermediate piston chamber 6 and the front end of the large piston chamber 3 near the end of the stroke of the piston, and the piston chamber 2 provided with an. exhaust ort 14 to exhaust the pressure fluid behind t e piston head 5 and thereby 4to permit the large effective piston area in the 4piston chamber 3 to .ov'erc'ome thesmaller effective piston area in the intermediate piston chamber 6. f It will'be noticed that the ports are pref-V erably so located as to permit running by of the pistonowingto its inertia. V The operation of the -preferred embodimentof my invention illustrated, is as fol lows:

Assumin the piston to be in the positlon shown in ig. 1` pressure iii-iid admitted through the inlet port 8 acts on the' inten mediate pressure area 9 and after assing through the by-pass port 10 acts on t crear pressure area l1 to drive the pistonforward. The smaller piston head 5 soon closes the inlet port 8 and the piston continues forward by the expansive action of the pressure fluid on the pressure areas 9 and 411. l

Substantially simultaneously 4with the closure of the port 8, the port 1l) is preferably closed. Thus there is a period of ressure expansionprovided in the piston c am 5o ,ber 2 and in the piston chamber 6. The exansion in the piston chamber 2, however, 1s much more rapid and completethan in the piston chamber 6, for the air in the latter increases but: little in volume as the p1st0n advances.

After the pistonvhead 4 passes the opening in. the return` port 18,.tl1e slightly expanded pressure fluid in the piston chamber 6 is opened into the piston chamber 3, the expanded pressure fluid in the chamber 2 having been exhausted through the' exhaust port 14. The effective pressure area of the piston in the intermediate pressure chamber 6 need not be nerhaustedxcptthrough the 'pstonchaumber 3, ,for Elie e ective pressure preventing ton, a ateral uidrinletoontrolledby said area of the intermediate iston chamber is preferably, as shown, Io relatively small area. Thus the expansionof pressure fluid in the chamber 3 will move the piston back to the osition showninFig. 1, when the cycle o operation will be repeated. 1

As shown in Figs. f3, ltand 5,1 prefer to useplural by-passgretufrn and exhaust orte; each' set of portsy preferably being ivided between cppositesides of the cylin- 70 der so that the impact and vpressure circumferentially4 is balanced on thepiston, thus undue pressure' between the cylinder and piston in any one direction and so reducing t e tendency of both to become worn.

The preferred arrangement of ports illus, trated, provides a single i eriod of pressure fluid admission, in a sing e charge, to actuate oneicomplete cycle of operation of the motor. When the piston closes the inlet port 8, all the pressure fluid in the cylinder is impelling the iston forward, yet no additional pressure uid need be admitted to return the piston. I find that I can' produce most satisfactory results by making the piston head 4 but little larger than the'piston head 5, thus providing but little effective pressure on the pressure surface 9 and utilizingthe reduced portion 7 as 96 a pressure Huid conveyin chamber in so far as it carries the pressure uid from the point of cui of the inlet port 8 .to the return port "my,

It. will be understood .that while I have shown and described 'a preferred construction of my invention, changes involving. omission,` substitution, alteration, and reversal of elements, may be made without de parting from the scope of my invention, which is best expressed in the following claims: l

1.' A valveless percussive` Huidmotor' comprising` 1n combination, a cylinder,'its pisiston, and co eratingpressure fluid de 1 ivering Lmeans or alternately distributing", in op site directions to, the opposite ends of sald cylinder a single charge of vpresi sure fluid during each ey le of reciprocation 1'115 of said piston in saidvoylinder. A

2. A valveless percussive fluid motor comprising, in combination, a. cylinder, 4its piston, a lateral fluid inlet controlled by said piston, and piston controlled pressure 'fluid istributing means for alternatel distributi- 1n in opposite directions to t e `op site ens 'of said cylinder a 'sin le oharge'o .presy sure uid during each cyc e olf-reciprocati'on' ofsaid piston inl Said cylinder.' 1,25

,3. A valveless' percuseive fluidmotor cour' pricing, in combination, acylinden'f a piston therein havin a plurality of 'heads and ali intermediate c am er,v a'lateral inlet-for admitting fluid to said intermediate Vchazn-l 130 -means for alternately distributing 5l. A valveless permissive ber, said inlet beingi opened and closed by said piston, and pressure Huid delivering in opposite directions to the opposite ends of said cylinder a single charge of fluid during each cycle ot reciprocation of said piston in said cylinder.

4. A valveless permissive fluid motor comprising, in combination, a cylinder, a piston therein having a plurality of heads and an intermediate reduced portion, a lateral fluid inlet opened and closed by one of said heads, and pressure fluid deliveringz means for alternately7 distributing in opposite directions to the opposite ends of said cylinder a single charge of pressure fluid during each cycle of reeiprocation of said piston in said cylinder.

5. A valveless permissive fluid motor conlprising, in eombination, a cylinder comprising* portions of different cross sectional area, a piston having heads fitting said cylinder portions respectively, a lateral fluid inlet opened and closed by one of said heads, and pressure fluid deliveringmeans for alternateljir distril'luting in opposite directions to the opposite ends of said cylinder a` single charge ol' pressure ilnid during each cycle of reeiprmzation of said piston in said cylinder.

G. A valveless permissive fluid motor comprisiug` in combination, a cylinder comprising portions of different cross sectional area, a piston having heads fitting said cylinder portions respectively, a` lateral fluid 1nlct opened and closed by one of said heads, and pressure fluid delivering means for alternatel)Y distributingl in opposite directions to the` opposite ends: ot said cylinder a single charge of pressure fluid during;l each cycle ot reciprocation of said piston in said cylluder.

7. A vali'eless percussive prisinff. in combination, a pluralitjf oi pressure anda intermediate piston movable in said let for admittingr fluid to said intermediate chamber and including a port opened and closed bv s aid piston, and cooperatingf pressure fluid delivering means for alternately distributing;- lluid from said intermediate chamber in opposite direct-ions to the opposite ends of said cylinder.

fluid motor comprising, in combination, a cylinder having a plurality,y ol' pressure chambers of different cross scctionalseaand an intern'iediatepressure chamber, a piston movable in said clvlindre having a pluralityoi headsof different cross sectional area, a fluid inlet for admit-- -iingf ,fluid to said intermediate chamber and including' :i pori opened and rlosiul liv said fluid motor coma cylinder havingl chambers therein pressure chamber, a cylinder', a fluid inpistou, anur ewipe-ratingr liressure fluid leliverung means for alt-ernatedj,v distributing said intermediate chamber in opfluid from said posxte directions to the opposite ends of cylinder.

9. A valveless permissive fluid motor comprising, in combination, a cylinder having a plurality of pressure chambers thereinl and an iutermedmte pressure chamber, a piston movable in said cylinder having` a plurality of heads, a fluid inlet for admittinu luidito said intermediate chamber 10. A valveless comprising, in com ination, a cylinder hav ing1 a pluralityv ot' pressure chambers therein and an intermediate pressure chamber, a piston movable in said c linderhaving a plurality of heads,

closed b v one of Isaid heads, Huid delivering means opened and closed by' different heads for` alternately distributing fluid from intermediate chambei` in opposite directions to the opposite ends of said cylinder.

valveiess permissive fluid motor comprising, in combination, a. cylinder and its piston, said piston and. cylinderpresenting,T a `plurality 0f pressure chambers and au intermediate pressure chamber, a fluid inlet for admitting fluid to said intermediate chamber and including a port opened and closed by said piston, and cooperating pressure fluid delivering means whereby during move-ment of said piston in one direction said intermediate pressure chamber is alternately connected with each of said other pressure chambers. i

l2. A valveless percussive fluid motor comprising, in Combination, a cylinder and its piston, said piston and' cylinder presenting a plurality of pressure chambers and an iutern'lediate pressure chamber, initial pressure fluid admission means opened and closed by said piston` and cooperatiup, conduit means for eonnrwtinpP lsaid intermediate pressure chamber with one ot' said pressure chambers and with the other pressure chamber after closure of said initial pressure fluidv admission means.

combination, a cylinder comprising' port ionsof dilferent cross sectional area, a piston havingr portions fitting said cylinder portions respectively, said piston and cylinder presenting a large pressure chamber, a smaller pressure chamber, and au intermediate pressure chamber, initial pressure 'fluid admission means opened and closed by said piston, and roiiperating conduit means for connectpercussive fluid motor ing said intermediate pressure chamber with one of said pressure chambers and with the other pressure chamber after closure of said initial pressure fluid admission means.

14. A percussive fluid motor comprising, in combination, a cylinder comprising portions of dilerent cross sectional arca, apiston having` portions tting said cylinder portions respectively, said piston and c linder presenting a large `pressure cham er, a small pressure chamber, and an intermediate ressure chamber, initial pressure fluid a mission means opened and closed by said piston and communicating through said intermediate chamber with a communi ating pressure chamber, and coperating conduit means whereby during movement of said piston in one direction said communicating pressure chamber is cut olf from and the other pres-- sure chamber connected to said intermediate chamber.

15. A valvelcss percussivefluid motor comprising, in combination, a cylinder comprising portions of different gross sectional area, a piston having `portions tting said cylinder portions respectively,l said piston and cylinder resenting a large pressure chamber, a smal er pressure chamber and an intermediate .pressure chamber, in1tial pressure fluid admission means opened and closed by said piston for admitting fluid to said intermediate pressure chamber, and cooperating conduit means for connecting said intermediate pressure chamber with one of said pressure chambers and with the other pressure chainber after closure of said initial pressure admission means.

i 16. A valveless percussive'iluid motor comrising, in combination, a cylinder comprislng portions of different cross. sectional area, a piston having portions fitting said cylinder portions respectively, said piston and cylinder presenting a large pressure chamber, a smaller pressure chamberz and an intermediate pressure chamber, initial pressure iluid admimion means delivering a predetermined volume of pressure fluid to said intermediate pressure chamber andone of said pressure chambers, and conduit means effecti 'e after closure Of said admission means and relatively little expansion oi. said pressure fluid in said intermediate pressure chamber, to admit said pressure Huid from said intermediate pressure chamber into the other of said pressure chambers to reverse the direction of reciprocation of said piston.

17. A valveless percussive fluid motor comprising, incombination, a cylinder audits piston, said cylinder and piston presenting a plurality of pressure chambers and an 1n termediate pressure chamber, initial pressure fluid admission means including a port opened and closed by said piston and communicating with said intermediate chamber. and valveless pressure fluid distributing fluid means controlled by said piston whereby fluid from said intermediate chamber is alternately conducted to and expanded in opposite ends of said cylinder.

18. A valveless percussive fluid motor coinprising, in combination, a cylinder and its piston, said cylinder and piston presenting a plurality of pressure chambers of different cross sectional areas and an intermediate pressure chamber, initial pressure fluid admission means including a port opened and closed by said piston and communicating with said intermediate chamber, and valvelcss pressure fluid distributing means controlled by said piston whereby fluid from said intermediate chamber is alternately conduct-ed to and expanded in opposite ends of said cylinder.

19 A valveless pressure fluid motor comprising, in combination, a cylinder comprising portions of different cross sectional area, a piston having portions fitting said cylinder portions respectively, said cylinder and piston presenting a large piston chamber, a smaller piston chamber, and an intermeditey piston chamber between the two, piston controlled communicating means between said intermediate chamber and one of the other pressure chambers, and coperating pressure fluid distributing means providing for the transfer in one direction of a predetermined charge of pressure fluid in said intermediate piston chamber to actuate said piston in thc opposite direction.

20. A pressure fluid motor comprising, in combination, a cylinder comprising portions of diiferent cross sectional area, a piston having portions fitting said cylinder 'portions respectively, said cylinder and piston presenting a large piston chamber, a smaller piston chamber, and an intermediate piston. chamber between the two, pressure duid supply means controllcd by the piston for admitting pressure fluid to said intermediate iston chamber, conduit means for conducting pressure fluid from said intermediate piston chamber to one of said other piston chambers to actuate said piston in one direction, and means eective after closure n said conduit means to admit pressure flui from said intermediate chamber to the other of said piston chambers.

21. A pressure fluid motor comprising, in combination, a cylinder, its piston, a plurality oi simultaneously eiectivc pressure fluid admission ports arranged at different points circum'ferentially of said cylinder intermediate its ends, and cooperating pressure iluid delivering meansior alternatel distributing to the opposite ends of said cyV inder a single charge of pressure duid for nach cycle of rcciprocation of said piston in said cylinder.

"A" A pressure fluid motor comprising, in

4J-1. combination, a cylinder, its piston, coperating pressure fluid controlling means for admitting to said cylinder intermediate its ends a single charge of pressure fluid for each cycle of reciprocation of said piston in cylinder and for distributing said c arge alternately to the opposite ends of said cylinder, and a plurality of simultaneously effective pressure arranged at different tially of said cylinder.

23. A pressure fluid motor comprising, in combination, a cylinder, its piston, coperating pressure fluid controlling means for admitting to said cylinder intermediate its ends a single charge of pressure Huid for each cycle of reciprocation of said iston in fluid exhaust ports points circumferen- 'said cylinder and for distributlng said charge alternately to the opposite ends of said cylinder, said means including a plurality of simultaneously effective pressure fluid admission and exhaust ports arranged at different points circumferentially of said cylinder.

Q4. A pressure fluid motor comprising, in combination, a cylinder, its piston, coperating pressure fluid controlling means for adm1tting to said cylinder intermediate its ends a single charge of pressure Huid for each cycle of reciprocation of said piston in said cylinder and for distributing said charge alternately to the opposite ends of said cylinder, said means including a plurality of simpltaneouslyeffective piston-controlled pressure fluid admission ports arranged at different points circumferentially of said cylinder. f

5. A pressure fluid motor comprising, in

combination, a cylinder, its piston, coperating pressure fluid controlling means for admitting to said cylinder intermediate its ends a single charge of pressure Huid for nach cycle of reciprocation of said piston in said cylinder and for distribvtlng said charge alternatel i to the oppositeends of said cylinder, said means including a plurality of piston-controlled pressure fluid conducting ports arranged rin substantially balanced relation at different points circumferentially of said cylinder.

26. In a percussive tool, a cylinder having a bore of two cross sectional areas and an intermediate groove of greater area, a piston hammer movabletherein havin an enlarged striking head and a smal er rear head, said piston having front, rear, and intermediate pressure surfaces of different areas, and means controlled by said piston and including a communication between said groove and the source of supply for admitting ressure to said last two surfaces to propel tie piston in one direction and subsequently admitting pressure from said groove to said front pressure surface to propel the piston in the opposite direction while closing communication 'between said groove and the source of supply.

In testimony whereof, I have signed my naine to this specification, in the presence of two subscribing witnesses.

GEORGE H. GILMAN. Witnesses:

DOUGLAS M. BARCLAY,

ILLIAM BAnoLAY. 

